Multiple parts together form a completed PCBA board, and then the components are connected through the pads, lines and traces on the laminated sheet of copper. This board comprises copper circuit layers embedded inside or mounted on a flat laminate composite substrate, which includes materials like fiberglass and composite epoxy.

It takes the form of a laminated sandwich structure of conductive and insulating layers: each of the conductive layers is designed with a pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto or between sheet layers of a non-conductive substrate.

A PCB serves as the foundation of an electronic device. It’s a flat board made of non-conductive material (like fiberglass) with thin copper traces laminated onto it. These traces act as pathways for electricity, connecting various electronic components mounted on the board.

The different types of PCB materials used in PCB from top to bottom includes Silkscreen, Soldermask, Copper and Substrate. The last of those layers, substrate, is made of fiberglass and is also known as FR4, with the FR letters standing for "fire retardant."